In a manufacture of semiconductor integrated circuits, film-forming and etching are performed on a substrate to be processed such as a semiconductor wafer or the like. Some of these processes are performed by using plasma, wherein radicals and ions are generated. These radicals and ions can move around to thereby adhere to the bevel surface and the backside of the substrate to be processed, thus forming a deposit layer. In the present specification, the adhering substances that form the deposit layer are referred to as bevel/backside polymers (BSP). Especially, during an etching process for etching the substrate to be processed, the quantity of the bevel/backside polymers adhering to the substrate to be processed increases.
The bevel/backside polymers per se have heretofore been disregarded because they have been considered to have no great influence on the manufacture of semiconductor integrated circuits. In recent years, however, there have been revealed influences on the manufacture of semiconductor integrated circuits, which are considered to be related with the bevel/backside polymers.
The following three patent documents disclose conventional examples for removing polymers or dust, although they are not directed to a technique of removing bevel/backside polymers or eliminating the influence of bevel/backside polymers.
Japanese Patent Laid-open Application No. 2005-142524 discloses a bonding surface treatment method of a semiconductor wafer before bonding, in which polymers are removed by dry cleaning, wet cleaning, polishing, plasma-treatment or brushing in order to enhance the bonding between two semiconductor wafers.
Japanese Patent Laid-open Application No. 2006-032653 discloses a method for fabricating a semiconductor device in which polymers are removed by wet etching using laser heating in order to reduce heavy metal contamination of a silicon substrate containing an OSF (Oxidation-induced Staking Fault) and a bonding leak current.
Japanese Patent Laid-open Application No. 2001-332606 discloses a method for fabricating a semiconductor device in which dust is sucked after brushing the backside of a semiconductor wafer in order to remove dust from the backside of the semiconductor wafer.